1. Field of the Invention
The present invention relates to an image formation apparatus and an inkjet recording apparatus, and more particularly to an image formation apparatus and an inkjet recording apparatus wherein the ejection face of a liquid ejection head is protected.
2. Description of the Related Art
Japanese Patent Application Publication No. 54-006541 discloses a protecting device of an inkjet head, which maintains a power supply to an apparatus main body until the inkjet head returns to its home position, when the power supply has turned off during travel of the inkjet head.
An inkjet recording apparatus carries out recording onto paper by a liquid ejection head while holding the paper by suction and conveying the held paper. In the event of an abnormality (abnormal halt) or an interruption of the power supply in the inkjet recording apparatus, it is not possible to maintain a power supply to the apparatus main body with the device disclosed in Japanese Patent Application Publication No. 54-006541, and hence there is a risk that the paper is not kept held by suction, then floats up and comes into contact with an ejection face of the liquid ejection head.
Japanese Patent Application Publication No. 2000-326478 discloses a printing apparatus having a shutter which is opened during image formation, and the image formation is carried out by advancing an inkjet head up to an image formation position, whereas when not performing image formation, the inkjet head is accommodated inside a cover and the shutter is closed. However, since the shutter is opened during image formation, there is a similar risk of the paper coming in contact with the ejection face of the liquid ejection head. Moreover, the shutter mechanism is disadvantageous because it is bothersome when carrying out maintenance of the ejection face, requires a large installation space, thus making the apparatus large in size, and increases costs.
Although it might be possible to withdraw a liquid ejection head from a paper suction conveyance device to a withdrawn position in the event of an abnormality or an interruption of the power supply, the paper comes into contact with the ejection face if the floating up of the paper from the suction conveyance device occurs earlier than the withdrawal of the head from the suction conveyance device to the withdrawal position.
In many cases, the paper is coated with treatment liquid in advance of the image formation, and if the paper comes into contact with the ejection face of the liquid ejection head, the ink in the liquid ejection head reacts with the treatment liquid on the paper and solidifies, thus causing critical damage to the liquid ejection head.